The Synthesis Application Of Acid Type Fluorocarbon Surfactant In Aqueous Film Forming Foams Extinguishing Agent

The amino acid type fluorocarbon surfactant was synthesized from RfCOOCH3[Rf=CF3CF2(C3F6O)n, n=2,3,4, derivatives of polyhexafluoropropylene oxide]. The product RfCONHCH2CH2N(CH2CH2COONa)2[Rf=CF3CF2(C3F6O)n,(n=2)] was characterized by MS, IR,1HNMR and19FNMR. We determined its physical and chemical characteristics in aqueous solution, such as surface activity, the chemical stability and so on. We applied the product comparing with DuPont1157and S200, then sieving out the best performance surfactant system. The results:through the figures of the MS, IR,1HNMR and19FNMR, the structure of amino acids fluorine carbon surfactant is (RfCONHCH2CH2N(CH2CH2COONa)2), Rf=CF3CF2(C3F6O)2and it is739g-mol-1. The surface tension can reach to16.7mN·m-1, it is better than DuPont1157. S200.We performed further studies on the surface properties such as surface tension, CMC, foam, interfacial absorption and etc. of this amino acid type fluorocarbon surfactant. Then we study the synergistic effects of a series of fluorocarbon-hydrocarbon surfactant compound system. Test result:the interfacial tension of the industry produce is about3.5mN·m-1and the surface tension is about17.7mN·m-1. The best fluorocarbon-hydrocarbon surfactant system was obtained with AOS:C8-10in a certain concentration. We found that the surface properties was increased by adding AOS:C8-10. The surface tension is about from19.0mN·m-1to17.7mN·m-1. So the best fluorocarbon-hydrocarbon compoud surfactant system was obtained from series tests and used in Aqueous Film Forming Foams Extinguishing (AFFF).Finally, the performance of AFFF was evaluated by some indoor methods such as the initial spreading coefficient, foam multiple,25%drainage time and so on. The suitable additives and concentration were screened out, and a new AFFF with low cost, high efficiency and environment protection was developed with laboratory fire experiment. The test result of the new product result indicates that all the targets of the product achieved the requests of the national criterion(GB17427-1998) aqueous film-forming foam fire extinguishing agents(AFFF). The surface tension and interfacial tension of the AFFF is very low, they are respectively19.3mN·m-1and2.5, these can made the initial spreading coefficient is positive and reach to3. The fire can be extinguished quickly in10s and the time of anti-burning can achieve to above15.0min. The main raw materials of AFFF are dependent upon importation from foreign countries for fluorocarbon surfactant. It can replace the PFOA and solve the problem.